Because so many students at the top universities have great ACT or SAT scores, I do recommend that students *consider* Subject Tests. You’ll only want to worry about them if you think that they can improve your testing portfolio. In the case of elite schools like Columbia, that means 750+ (or at least 700+). You can try tests from the Official Guide published by College Board. Fewer schools than ever are requiring the Subject Tests — especially with ACT scores. It would be a little challenging to fit them in (including preparing for them) as senior year starts and application season begins, so you may want to just sit tight with your ACT score.
The corresponding percentile of each scaled score varies from test to test—for example, in 2003, a scaled score of 800 in both sections of the SAT Reasoning Test corresponded to a percentile of , while a scaled score of 800 in the SAT Physics Test corresponded to the 94th percentile. The differences in what scores mean with regard to percentiles are due to the content of the exam and the caliber of students choosing to take each exam. Subject Tests are subject to intensive study (often in the form of an AP , which is relatively more difficult), and only those who know they will perform well tend to take these tests, creating a skewed distribution of scores.